In lupus cystitis, is the urinary tract dilated or obstructed?

Abstract Objectives Lupus cystitis is a rare but serious complication of systemic lupus erythematosus (SLE) that can cause permanent bladder dysfunction, leading to irreversible deterioration of kidney function. We report two cases of SLE with lupus cystitis who showed different images from the same cause of disease. Methods Patient 1, a 67‐year‐old woman diagnosed with SLE presented with persistent dysuria for 3 weeks with sudden headache and vomiting. She was hospitalized because of acute kidney injury; the serum creatinine level was 10.68 mg/dL. Computed tomography (CT) showed significant bilateral ureteral stenosis and bilateral hydronephrosis. Patient 2, a 45‐year‐old woman diagnosed with SLE presented with dysuria requiring self‐catheterization. CT showed significant bilateral ureteral dilatation and bilateral hydronephrosis. Results In patient 1, the right kidney was afunctional. Left nephrostomy was performed on Day 2. Her serum creatinine returned to the normal range. In patient 2, After admission, she changed to an indwelling bladder catheter. Her serum creatinine level improved from 2.04 to 1.31 mg/dL. Conclusion In patients with lupus cystitis, the urinary tract is commonly dilated, but stenosis has been seen in rare case. Physicians should be careful in diagnosing it.


| INTRODUCTION
Lupus cystitis is a rare but serious complication of systemic lupus erythematosus (SLE) that can cause permanent bladder dysfunction, leading to irreversible deterioration of kidney function. 1 We report two cases of SLE with lupus cystitis who showed different images from the same cause of disease.

| CASE PRESENTATION
These two cases were patients with SLE, and they hospitalized because of acute kidney injury due to bilateral hydronephrosis. They showed different images from the same cause of disease. Patient 1, a 67-year-old woman diagnosed with SLE (polyarthritis dominant) overlapped with limited-type systemic sclerosis at age 15 years, presented with persistent dysuria for 3 weeks with sudden headache and vomiting. She was hospitalized because of acute kidney injury; the serum creatinine level was 10.68 mg/dL. Computed tomography (CT) showed significant bilateral ureteral stenosis and bilateral hydronephrosis ( Figure 1A). Patient 2, a 45-year-old woman diagnosed with SLE at age 28 years (serositis dominant), presented with dysuria requiring self-catheterization. Initially, she prioritized fertility treatment and refused immunosuppressive therapy. However, 4 years later, immunosuppressive therapy was started for ileus due to lupus enteritis and bilateral hydronephrosis due to lupus cystitis. Uroflowmetry at the age of 40 revealed the urine volume of 149.3 mL, the maximum urine flow rate of 5.9 mL/s, and the residual urine volume of 109 mL, suggesting urination disorder due to lupus cystitis. At the age of 46, the postvoid residual urine volume was 343 mL. She refused cystoscopy and bladder biopsy. CT showed significant bilateral ureteral dilatation and bilateral hydronephrosis ( Figure 1B).
In patient 1, the right kidney was afunctional. Left nephrostomy was performed on Day 2. Her serum creatinine returned to the normal range. We performed the retrograde pyelography on Day 19. However, neither the catheter nor even the guidewire had passed into both ureters, and we concluded that ureteral stenoses were from the ureteropelvic junction to ureterovesical junction on both. Figure 2 shows cystoscopic findings that the multiple reddish bladder mucosal lesions. She was discharged on Day 38. Bladder biopsy demonstrated interstitial cystitis associated with SLE such as dense lymphocytic cell infiltration with increased plasma cells, epithelial denudation, and stromal edema and fibrosis ( Figure 3). In patient 2, After admission, she changed to an indwelling bladder catheter. Her serum creatinine level improved from 2.04 to 1.31 mg/dL. She was discharged on Day 13.

| DISCUSSION
Chronic and unresolved lupus cystitis can cause structural changes in the urinary tract because dysfunction of the ureterovesical junction caused reflux. 2 In patient 2, F I G U R E 1 (A) Significant bilateral ureteral stenosis (yellow arrows) and bilateral hydronephrosis. (B) Significant bilateral ureteral dilatation and bilateral hydronephrosis.
F I G U R E 2 Cystoscopic findings. Patient 1 shows the multiple reddish bladder mucosal lesions (yellow arrows).
we considered that bilateral ureteral dilation and hydronephrosis resulted from just the bladder contraction. In patients with lupus cystitis, the urinary tract is commonly dilated 3-5 but stenosis has been seen in rare case. 6,7 Physicians should be careful in diagnosing it.